Pandion was exiled from Athens by the sons of his uncle Metion who sought to put Metion on the throne. Pandion fled to Megara where he married Pylia, daughter of King Pylas. Later, Pylas went into voluntary exile to Messenia, because he had killed his uncle, Bias. Pylas then arranged for his son-in-law to be king of Megara. Pylia bore Pandion his four sons. When Pandion died at Megara, Nisos succeeded him as king. He had a hero shrine at Megara at the Bluff of Athene the Diver-bird. After this death, his other sons returned to Athens and drove out the sons of Metion, putting Aegeus on the throne.

Either Pandion II or Pandion I was usually identified with Pandion, the eponymous hero of the Attic tribe Pandionis.

^According to Kearns, p. 192, "originally there was only one Pandion"; but see Gantz, p. 235. Harding, p. 42 says: "It is usual to believe that one or the other of the two was invented for the purpose of fixing the chronographic calculations".